1. Field of the Invention
The present invention relates to a mucosa excising device using an endoscope which sucks a mucosa into a cylindrical cap (which is also referred to as a hood) attached to an end of an insertion portion of the endoscope and excises a polypous base part of the mucosa by using a high-frequency snare.
2. Description of the Related Art
In recent years, there has been conducted an endoscopic mucosal resection which excises a mucosa at a diseased part by using an endoscope without performing a laparotomy with respect to an esophageal or gastric cancer at an early stage. As one of such methods, there is known a method disclosed in Jpn. UM Appln. KOKAI Publication No. 6-75402 and Jpn. Pat. Appln. KOKAI Publication No. 2001-275933. This method conducts an endoscope mucosal resection using a high-frequency snare by secondarily utilizing a cap attached to an end of an insertion portion of an endoscope. In such a method, an end of a snare sheath of the high-frequency snare is led into the cap attached to the end of the insertion portion of the endoscope through a channel of the endoscope, a snare wire is caused to protrude from this end, and a loop of the protruding snare wire portion is formed over an inner part of a claw portion formed on the entire periphery of the end edge of the cap (which will be referred to as a looping operation hereinafter). The mucosa is sucked into the cap, then a base portion of the mucosa is constricted by using the looped wire portion of the high-frequency snare, and the high-frequency snare is energized in order to excise the mucosa.
There is known a method which conducts an endoscopic mucosal resection without requiring the looping operation in a body cavity as disclosed in Jpn. Pat. Appln. KOKAI Publication No. 9-187415 and Jpn. Pat. Appln. KOKAI Publication No. 9-66019. In this method, a wire loop of a high-frequency snare is previously engaged on an outer periphery of a cap in the form of a loop outside the body, and a looped wire portion is inserted into the body.
Further, there is also known a method such as disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2002-45369. In this method, the snare wire is looped along the inside of a claw portion formed over the entire periphery of the end edge of the cap, and it is fixed by means of an adhesive.